I can answer the first question, yes ranchers can lease blm. Te lease the grazing rights though. It is still public land, you can hunt it and do whatever else you want on it besides release your livestock on it. And a map would not show leased land because it does not effect the public. Be forewarned alot of ranchers will try to claim public land that isn't theirs and try to kick you off of it. Buying the most up to date maps at the blm office is the best thing you can do. They are a must for anywhere you hunt or plan on hunting. It's as important as your weapon and boots.